| 摘要 |
Chlorinated polybutene-1 containing 26 to 40 weight per cent of chlorine, may be prepared by dissolving 5 to 15 weight per cent of polybutene-1 having a melt index greater than 0.1 in a solvent and reacting with chlorine at 55 DEG to 65 DEG C. in the presence of a chlorination catalyst. The solvent may be a halogenated aliphatic or aromatic hydrocarbon, and the catalyst may be ultra-violet light or an organic peroxide. The products may be compounded with stabilizers, e.g. organotin compounds, barium, calcium and lead salts, epoxy resins and epoxidized fats and oils; and may be formed into heat-shrinkable films by extruding, calendering or solvent casting, or heat-shrinkable foams by expanding with blowing agents such as methylene chloride, acetone, methyl ethyl ketone, azobisformamide, azobisisobutyronitrile, N,N1 - dinitrosopentamethylene tetramine, benzene-1,3-disulphonyl hydrazide, diphenylsulphone - 3,31 - disulphonyl hydrazide, 4,41 - oxybis(benzene sulphonyl hydrazide) and N,N1-dimethyl-N,N1-dinitrosoterephthalamide, or pressurized nitrogen or carbon dioxide. In examples (I-VI and XIV) polybutene-1 is chlorinated in carbon tetrachloride in the presence of benzoyl peroxide, and the chlorinated polybutenes are (XV and XVI) blow extruded to form heat-shrinkable films and (XVII) expanded with azobisformamide to form a foamed sheet. The foam may be warmed, compressed and cooled and re-expanded by heating. |
